X-band Frequency Research Articles

Replacing the Gallium Oxide Shell with Conductive Ag: Toward a Printable and Recyclable Composite for Highly Stretchable Electronics, Electromagnetic Shielding, and Thermal Interfaces.

Liquid metal (LM)-based composites hold promise for soft electronics due to their high conductivity and fluidic nature. However, the presence of α-Ga2O3 and GaOOH layers around LM droplets impairs conductivity and performance. We tackle this issue by replacing the oxide layer with conductive silver (Ag) using an ultrasonic-assisted galvanic replacement reaction. The Ag-coated nanoparticles form aggregated, porous microparticles that are mixed with styrene-isoprene-styrene (SIS) polymers, resulting in a digitally printable composite with superior electrical conductivity and electromechanical properties compared to conventional fillers. Adding more LM enhances these properties further. The composite achieves EMI shielding effectiveness (SE) exceeding 75 dB in the X-band frequency range, even at 200% strain, meeting stringent military and medical standards. It is applicable in wireless communications and Bluetooth signal blocking and as a thermal interface material (TIM). Additionally, we highlight its recyclability using a biodegradable solvent, underscoring its eco-friendly potential. This composite represents a significant advancement in stretchable electronics and EMI shielding, with implications for wearable and bioelectronic applications.

Design of compact signal source with reduced phase noise for airborne pulse Doppler RF sensor

Abstract In this article, a low phase noise signal source to be used as local oscillator in pulse Doppler radio frequency (PDRF) sensor is proposed. Innovative design techniques for realization of the low phase noise frequency source using phase-locked loop (PLL) and dielectric resonator (DR) are presented. Qualitative investigations have been carried out on the effect of phase noise in PDRF sensor performance. An X-band vibration resistant PLL-based frequency source with phase noise better than −95 dBc at 1 kHz frequency offset has been designed here. It also presents the design of a 7.6 GHz low phase noise, vibration resistant DR oscillator. Systematic analysis of the key design aspects, their thermal-vibrational stability, and ease of integration with hybrid microwave integrated circuits have been disclosed. A prototype board is fabricated, assembled in a compact mechanical enclosure of dimension 55 × 55 × 15 mm3. Finally, developed module is experimentally validated under 7.6 g rms magnitude random vibration test in three axes and compared results with other state of-the-art similar works. The comparison clearly shows the merit of present research work over other similar existing works.

Hybrid rib fabric electromagnetic shielding measurement in X-band

This study involves measurement and evaluation of the electromagnetic shielding effectiveness (EMSE) in the X-band frequency range of rib-knitted fabrics formed from hybrid conductors. Hybrid conductive fabrics were made by knitting copper, silver, and stainless steel conductors together with cotton yarn. The basic theory of EMSE is introduced, and the waveguide measurement setup described. The through-reflect-line calibration setup was used to obtain accurate results. After calibration of the established waveguide measurement setup, hybrid conductive fabrics were tested. The measurements were analyzed and the fabrics compared. The aim is to produce a hybrid fabric that is suitable for general use, has a good EMSE, is easy to produce, and offers low-cost high-frequency solutions. An easy-to-produce and low-cost EMSE material is required, especially in new-generation wearable flexible electronic devices and military applications.

Tailoring SrFe12O19 – MoS2 composites for enhanced microwave absorption performance in X-band

The electromagnetic wave-absorbing composites, incorporating strontium hexaferrite and molybdenum disulfide (SrFe12O19-MoS2), are synthesized by mixing in different weight ratios. In the present work, strontium hexaferrite (SrFe12O19) is developed through a low-temperature auto-combustion method while two-dimensional molybdenum disulfide (MoS2) is synthesized by a facile hydrothermal process. The materials and their composites undergo analysis using characterization techniques such as X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), and vibrating sample magnetometer (VSM) to assess their structural, morphological, and magnetic properties, respectively. The minimal reflection loss (RLmin) of – 47.35 dB is observed at 8.66 GHz for the SrFe12O19-MoS2 (50 %-50 %) composite cast into pellets for microwave absorption analysis in the X-band frequency range. This RLmin is obtained with a sample thickness of 1.7 mm. An adequate bandwidth of 3.1 GHz, representing 77.5 % of the entire X band, is observed for a loss below −10 dB. The synergistic interaction between magnetism and dielectricity makes it an efficient electromagnetic absorber for modern technologies.

A novel engineered sandwich composite with ceramic-coated graphite fibre-reinforced face sheets and an auxetic core for enhanced broadband electromagnetic absorption: design using multiscale computational analysis

Abstract A novel sandwich composite is designed for enhanced broadband absorption using a multiscale computational analysis. The sandwich panel is configured with BaTiO3 coated graphite fiber reinforced polymer (C-GFRP) composite, while BaTiO3 based auxetic material is used as the core material. A computationally efficient in-house tool based on the variational asymptotic method is used to homogenise the electromagnetic properties and evaluate the reflection loss characteristics of the proposed sandwich structure using the scattering matrices. A detailed parametric study of 300 analyses is conducted to identify the optimal sandwich panel configurations for achieving broadband reflection loss under the normal incidence of transverse electric (TE) and transverse magnetic (TM) polarised waves. Two different configurations have been obtained, satisfying the requirements of broadband reflection loss in the X-band frequency range. Configuration (a) Vf = 15% without any ceramic coating, and configuration (b) Vf = 20% with ceramic coating volume fraction (Cf) of 70%. Configuration (a) and (b) maintained the desired reflection loss of greater than -10 dB up to an incidence angle of 40◦ and 60◦, respectively. With the demonstrated capability of covering the entire broadband frequency range, the proposed configurations can serve as baselines to explore novel ceramic-based engineered composite architectures for broadband absorption applications.

Comparison of Microwave Adsorpsion of Core-Shell Fe3O4@SiO2 by Different Methods

Abstract In this research, magnetite nanoparticles coated with sillica from rice husk ash (core-shell Fe3O4@SiO2) were synthesized by a modified stöber method through hydrolisis of silica using basic catalyst. Phase composition, morphology and microstructure were characterized using XRD, SEM, and TEM. The result shows that the sillica shell was successfully coated the core of nanoparticles magnetite. Core-shell Fe3O4@SiO2were synthesized using two method, first silica extraction and second through the silica gel. The application on microwave absorption are measured using VNA at the X-band frequency (8-12 GHz). Materials reach a reflection loss value of -34,29 dB at a frequency of 10,98 GHz for the first method (extraction of silica). For the second method (through silica gel), it exhibits two maximum absorptions with a reflection loss value under -20 dB, which are -23,05 dB at a frequency of 10,1 GHz and -25,03 dB at a frequency of 10,98 dB.

Role of Pb(Zr0.52Ti0.48)O3 on Electric, Dielectric, Electromagnetic Wave Absorption Characteristics of Multiferroic Nanocomposites for Magnetoelectric Devices

Multiferroic composites of ferrite and ferroelcectric phases with systematically varying concentration (100-x)Mg0.48Cu0.12Zn0.4Fe2O4 + x Pb(Zr0.52Ti0.48)O3 (MCZPZT) ( where, x mol% = 0, 20, 40, 50, 60, 80, 100) were prepared by mechanical alloying and sintering methods. The dc resistivity and dielectric constant of the samples as a function of temperature were studied in detail and obtained results are reported. The magnetoelectric effect was investigated for the composites. The sample with 80% ferroelectric phase (MP5), shows largest magnetoelectric output voltage coefficient (dE/dH) H value of 880 μVcm.Oe at 2000 Oe magnetic field. Electromagnetic interference shielding properties of transmission loss and attenuation constant were determined for the composites. Skin depth decreases with frequency from 0.29 to 0.2 cm in the range 8–12 GHz for all composites. The composite MP5 with 80% PZT shows lowest α value between 282 dB m−1 and 414 dB m−1 throughout X-band frequencies. The present results proved that the current magnetoelectric materials of all concentrations exhibit strong magnetoelectric coupling with excellent microwave absorbing performance in X-band region and are appropriate for EMI shielding and novel device applications.

Valorization of Ricinus communis outer shell biomass to biochar: Impact of thermal decomposition temperature on physicochemical properties and EMI shielding performance

The rising awareness of electromagnetic pollution has increased interest in renewable and ecologically sustainable materials for shielding electromagnetic waves. Research on carbon-based electromagnetic wave absorption materials derived from agro waste is widely explored due to their advantageous characteristics, including low density and consistent physicochemical properties. The research aims to produce biochar with maximum carbon content from Ricinus communis outer shell (RCOS) and to examine the characteristics of biochar/epoxy composites for their application in electromagnetic (EM) shielding. In this study, the composite made from RCOS-based biochar was effectively developed using slow pyrolysis at 400 °C–700 °C. The characterisations of enhanced properties of biochar were conducted by using yield analysis and proximate analysis, elemental analysis, field emission scanning electron microscope (FE-SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), electrical conductivity. The biochar pyrolysis results revealed that the biochar yield, fixed carbon and maximum carbon content were 30 wt%, 50.49 wt% and 79.2 wt%, respectively, at 700 °C. Fourier transform infrared (FTIR) spectroscopy revealed that for the biochar at 700 °C, C=C and C-H functional groups were present, and the others were eliminated as volatile gases during biochar production. TG analysis demonstrated higher biochar stability with residues of 75 % for 700 °C. The biochar produced at 700 °C possesses the maximum electrical conductivity of 95 S/m due to the presence of graphitic carbon. The vector network analyser (VNA) measured a maximum shielding efficiency of 26.5 dB in the X-band frequency when adding 40 wt% biochar prepared at 700 °C to the epoxy matrix. The results suggest that the RCOS biochar/epoxy composites have promise as a novel type of absorbent materials because of their low density, lightweight structure, and extensive absorption capacities. These biochar-based lightweight composites can be used as a shielding material for electronic enclosures, telecommunication equipment, and aerospace applications.

Microwave absorption studies in X-band of magnetized barium hexaferrite

Abstract To enhance the magnetic and microwave absorbing properties, barium hexaferrite, BaFe12O19, was studied in the x-band (7–13 GHz) frequency range. The BaFe12O19 was prepared as non-magnetized and magnetized samples. The crystal structure, surface morphology, magnetic and microwave absorption of BaFe12O19 were studied with X-ray diffraction (XRD), optical microscope, permagraph and vector network analyzer (VNA), respectively. XRD result showed the formation of M-type hexagonal polycrystalline structure. The hysteresis loop results verified the formation of permanent magnet with high saturation magnetization. The VNA results showed that reflection loss and absorption were − 71.07 dB and 67.96% for magnetized barium hexaferrite, respectively.

Design and experimental investigation of an origami inspired X-band accordion waveguide

This paper presents design, numerical analysis and experimental investigation of an origami inspired X-band accordion waveguide that is aimed to create a flexible and adaptive solutions. The design process is conducted in a Finite Integration Technique (FIT) based microwave simulation software to model and simulate the proposed waveguide, and that shows structural benefits of origami technique based paper folding. Proposed waveguide model is numerically analyzed under both X and Y bending with 30˚, 60˚, 90˚ and 120˚ bending angle to provide its flexibility. Besides, the electric and magnetic field distributions were also obtained and explained in details to provide working mechanism of the proposed accordion waveguide. The S21 transmission characteristics between ports exhibits a decrease of 0.015 dB in numerical results, which is negligible and acceptable in applications. The experimental results demonstrate that the proposed waveguide has effective transmission characteristics within the 8–12 GHz X-band frequency range, with a satisfactory S21 transmission parameter. The numerical and experimental results show that proposed origami inspired accordion waveguide has a huge potential for application in dynamic microwave and satellite components.

Structural, Morphology and Electromagnetic Interference Shielding Studies of Multifunctional Hybrids of Low-Density Polyethene with Graphene, Carbon Nanotube and Magnetite

ABSTRACT In this study, we investigate the EMI SE (Electromagnetic interference shielding effectiveness) of novel multifunctional polymer hybrids in the X-band and Ku-band frequencies. Magnetite nanoparticles were synthesized via wet chemical reduction and nanographene was synthesized through chemical exfoliation combined with microwave treatment. Nine different composites were prepared with varying weight ratios of graphene and magnetite. X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed their structural and morphological properties. SEM analysis revealed magnetite particle sizes ranging from 10.05 nm to 29.8 nm. Vibrating Sample Magnetometer (VSM) analysis indicated that the magnetite nanoparticles exhibit super paramagnetic behavior with a magnetic anisotropy constant (K) of approximately 63.9375 × 106 J/m3. Impedance analysis, permittivity and permeability measurements showed frequency-dependent behaviors, with interfacial polarization effects due to magnetite agglomeration. The highest conductivity, observed in the 50:5:37.5:7.5 hybrid, peaked at 8 S/cm at lower frequencies. The 50:5:37.5:7.5 hybrid demonstrated the highest EMI SE of 50.08 dB (99.999019% suppression) in the X-band, which is suitable for advanced EMI-shielding applications.

Exceptional electromagnetic interference shielding using single-walled carbon nanotube/conductive polymer composites films with ultrathin, lightweight properties

The fundamental integrity of electronic devices depends heavily on appropriate electromagnetic protection measures. In this work, thin films of single-walled carbon nanotubes (SWCNTs) and poly(3,4-ethylene dioxythiophene): poly(styrene sulfonate) composites are presented, and their electromagnetic interference shielding effectiveness (EMI SE) is assessed in the X-band frequency range. The films are prepared via a simple benchtop process involving a vacuum filtration followed by a dip-coating. Notably, the composite with the highest thickness, measuring 2.12 μm, achieved the highest EMI SE of 55.53 dB, whereas the thinnest, measuring 0.24 μm, exhibited the highest specific SE divided by thickness (SSE/t) of 2,230,000 dB·cm2·g−1. Additionally, the composites demonstrated excellent physical and chemical stability, maintaining their performance under various harsh conditions. The highest shielding performance of our composite films among reported carbon-based polymer materials is attributed to the complementary spatial arrangement of inherently conducting materials, namely, the SWCNT and the conducting polymer. Our contribution here lays the groundwork for creating lightweight, flexible composites with superior EMI shielding performance, targeting next-generation flexible electronics.

Influence of SWCNT on shielding and tensile properties of polyurethane nanocomposites

ABSTRACT The effect of single-walled carbon nanotubes (SWCNTs) as fillers in polyurethane matrix composites on the efficiency of attenuating electromagnetic waves in the X-band region (8–12 GHz) was studied in the current work. To meet the present-day challenges, the composites were tested using a tensile system. The inclusion of SWCNT in the polyurethane matrix proved the enhancement of electromagnetic interference shielding performance along with the improved mechanical properties. The composites were characterised by FTIR and FESEM. The dielectric properties were investigated in X-band frequencies. The shielding performance of the samples was found to be 28 dB for 1 wt% filler at 10 GHz. The effect of CNT on the mechanical performance of polyurethane composites was studied. The maximum tensile strength achieved was 2.87 MPa for 3 wt% CNT. The results showed that the synthesised sample materials found more shielding applications with favourable tensile properties.

Cellulose-reinforced foam-based phase change composites for multi-source driven energy storage and EMI shielding

To address the increasingly serious environmental pollution and energy crisis, there is an urgent need to develop multi-source-driven energy storage materials, the field of new energy sources, such as solar thermal power generation, but electromagnetic pollution has become a primary problem that needs urgent resolution. Therefore, the development of multifunctional phase change composites (CPCMs) with multi-source drive capabilities and excellent electromagnetic shielding integration is crucial. In this study, polypyrrole (PPy)-coated conductive fibers were crosslinked with polyvinyl alcohol (PVA) to form a three-dimensional network, which was then combined with metal foam to prepare Ni–F/PPy@CNF-PVA (PCN) dual-network carriers with high electrical conductivity by vacuum-assisted adsorption and freeze-drying methods. Polyethylene glycol (PEG) was subsequently encapsulated via vacuum impregnation to get the shape-stable PEG/Ni–F/PPy@CNF-PVA (PPCN) phase change composites. The PPCN exhibited good stability and high energy storage density (melt enthalpy up to 126.18 J/g, relative enthalpy efficiency over 99 %). Benefiting from its outstanding electrical conductivity (186680 S/m for PPCN-3), light-absorbing properties, and magnetism, the PPCN also exhibits highly efficient photothermal, electrothermal, and magnetothermal conversion capabilities. The electromagnetic interference shielding efficiency reaches up to 110.37 dB within the X-band frequency range (8.2–12.4 GHz). In conclusion, PPCNs are significant for multi-source-driven energy storage and electromagnetic shielding.

Advanced ternary carbon-based hybrid nanocomposites for electromagnetic functional behavior in additive manufacturing

This study explores the processing and performance of acrylonitrile butadiene styrene (ABS)-based carbon ternary hybrid nanocomposites, incorporating carbon nanotubes (CNT), graphene nanoplatelets (GNP), and carbon black (CB), for applications in electromagnetic compatibility (EMC). The effect of nanocomposite processing on electromagnetic properties was evaluated by varying the mixing protocol, either through direct extrusion with simultaneous addition of all constituents or by preparing a master batch followed by dilution. The impact of nanofiller morphology and processing techniques on the behavior of nanocomposites was systematically investigated. Filaments of these nanocomposites were Additive Manufactured via Material Extrusion, and the resulting parts were evaluated for EMI shielding effectiveness (SE) in the X-band frequency range. The study reveals that the morphology, influenced by the processing strategy, significantly impacts the EMI SE properties of the printed samples. Particularly, ternary hybrids 3/3/3 wt% (CNT/GNP/CB) nanocomposites demonstrate promising electrical (0.003 S/cm), electromagnetic (29 dB of total attenuation), and mechanical performance (elastic modulus of 3080 MPa), with a clear advantage observed in those processed via direct extrusion. These nanocomposites were validated as feedstock filaments for 3D printing, and the printed sample exceeds the injection molded behavior for the composition 3/3/3 wt% (CNT/GNP/CB), achieving 40 dB of total attenuation at 11.8 GHz. The findings contribute valuable knowledge into tailoring nanocomposite formulations for additive manufacturing applications in EMI shielding, providing a nuanced understanding of the interplay between processing strategies, nanocomposite morphology, and resulting material properties.

Microwave Absorption Performance of Flexible Porous PVDF-MWCNT Foam in the X-Band Frequency Range.

Lightweight electromagnetic absorbers made of polymers and multiwall carbon nanotubes (MWCNTs) have attracted a lot of attention because of their potential to shield next-generation electronics devices from electromagnetic radiation without reflecting it back into space. In this research, a flexible foam composed of MWCNTs and polyvinylidene fluoride (PVDF) is developed. This foam is designed to be an electromagnetic shielding material that is both flexible and absorption-dominant, reducing electromagnetic interference. The solvent approach is used to fabricate the PVDF-MWCNT foam. It is discovered that the foam has a porosity of 88.9%. Each cell in the PVDF-MWCNT foam is formed in a porous layered manner. The foam demonstrates a dielectric constant (ϵ ' ) of around 7.19 and dielectric loss (ϵ " ) of 4.46 at 9.96 GHz as calculated from MATLAB using the Nicolson-Ross-Wire algorithm. This developed EM absorber exhibits a high shielding efficiency of 78.46 dB. With an ideal reflection loss of -26.5 dB, this absorber attains the desired outcomes. The electromagnetic shielding performance is supported by calculations of the impedance matching degree, which was found to be 0.54. The PVDF-MWCNT foam displayed absorption-dominant characteristics, with a significantly low shielding due to reflection. This newly developed foam EM absorber has proven itself capable in a variety of commercial and stealth-related applications.

Microwave-absorbing behavior of rare-earth-ion-doped copper manganese nanoferrites in X-band frequency

In this study, the technology important Cu0.5Mn0.5Fe2O4 and Cu0.5Mn0.5Fe1.80RE0.2O4 (RE = La, Gd, Nd, and Dy) nanoferrites were synthesized via sonochemical method and characterized to overcome the electromagnetic pollution problems. Crystalline, morphological, electrical, magnetic, and microwave-absorbing parameter were identified by doping of RE (La, Gd, Nd, and Dy) in Cu0.5Mn0.5Fe2O4 nanoferrites. The XRD analysis revealed a cubic spinel structure with a single-phase composition for Cu0.5Mn0.5Fe2O4 nanoferrites whereas Cu0.5Mn0.5Fe1.80RE0.2O4 (RE = La, Gd, Nd, and Dy) nanoferrites had a cubic structure with the presence of a secondary phase. SEM images confirmed the spherical shape of the particle and the grain size within the range of 19.25–28.19 nm, with elemental stoichiometry confirmed by EDS spectra. The dielectric constant and conductivity of Cu0.5Mn0.5Fe1.80RE0.2O4 nanoferrites were low at higher frequencies, which lead good candidates for microwave-absorbing technologies. The substitution of RE decreases saturation magnetization (43.38–23.96 emu/g) and squareness ratio values of prepared nanoferrites were less than 0.5. The SET values of the prepared nanoferrites were in the range of 32.31–41.81 dB. The minimal reflection loss (RL) values of Cu0.5Mn0.5Fe2O4 and Cu0.5Mn0.5Fe1.80RE0.2O4 nanoferrites were less than 10 dB and which indicated that the prepared nanoferrites possessed great potential for applications as microwave-absorbing materials.

Enhanced multifunctionality in carbon fiber/carbon nanotube reinforced PEEK hybrid composites: Superior combination of mechanical properties, electrical conductivity, and EMI shielding

This study presents a novel approach to manufacturing carbon fiber and carbon nanotube-reinforced PEEK hybrid composites (CF/CNT/PEEK) using compression molding. The hybrid composite characteristics were compared with those of a control composite (CF/PEEK). Various tests were conducted on both composite types to investigate the impact of incorporating a carbon nanotube sock layer (an ultra-thin layer of a low-density CNT network), including three-point bend, electrical conductivity, and EMI shielding. The research also underscored the importance of EMI shielding simulation. An important aspect of the study involved performing multiscale simulations on control and hybrid composites, employing a digital twin methodology, and validating the results with experimental findings. For the hybrid composite, double multiscale simulations were performed by integrating two local-scale models, a CF/PEEK unit cell (micro-scale) and a CNT/PEEK representative volume element (RVE) (nano-scale), into a global-scale model. A detailed post-processing analysis of the simulation results was conducted to analyze stress distribution on local and global scale models. It was noted that there was an over 8 % increase in the flexural strength of the hybrid composite, along with a reduction of over 27 % in the standard deviation of the results. The introduction of CNTs enhanced the electrical conductivity by more than 36 %. It conferred remarkable EMI shielding effectiveness exceeding 50 dB across the entire X-band frequency range, attributed to enhanced reflection and absorption. EMI shielding simulations suggest that refining the manufacturing process of the hybrid composite could enhance its shielding properties. The developed multiscale simulation has been demonstrated as an efficient prediction tool, as the simulation outcomes closely align with experimental findings. The resultant hybrid composite is promising for potential multifunctional applications.

Evaluation of the shielding effectiveness of electrodeposited Zn–Ni, Zn–Co, Ni–Co, and Zn–Ni–Co alloy coatings

This paper investigates the effect of different alloy coatings (Zinc–Nickel (Zn–Ni), Zinc–Cobalt (Zn–Co), Nickel–Cobalt (Ni–Co), and Zinc–Nickel–Cobalt (Zn–Ni–Co)) on surface properties and electromagnetic interference (EMI) shielding effectiveness. These alloy coatings are electroplated on the surface of copper material in a sulfate bath using a power supply. The coating composition, morphology, and phase structures of the alloy coatings are examined by Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD); absorption and electromagnetic shielding values in the X-band frequency range are investigated by Vector Network Analyzer (VNA) using coaxial holder method. According to the results of the surface morphology of the alloy coatings, the expected surface structures are generally formed. XRD results also reveal phases that differ according to alloy type. As a result of this study, it is determined that the best electromagnetic shielding efficiency is found in Zn–Ni–Co alloy coating whereas Ni–Co alloy coating has the best absorbance value. Based on these results, such binary and ternary metal alloy coatings can be considered as a decent alternative to increase shielding efficiency for materials such as copper, which already have good conductivity and a certain level of shielding.

Hexagonal boron nitride nanosheets/graphene nanoplatelets/cellulose nanofibers-based multifunctional thermal interface materials enabling electromagnetic interference shielding and electrical insulation

Thermal interface materials (TIMs) that block electromagnetic interference (EMI) and current leakage are essential for high-density, high-power devices and compact form factors of electronic and mobility platforms. However, their coupled thermal-electrical-electromagnetic characteristics involve mismatches in thermal conductivity, electrical insulation, and EMI shielding, limiting the multifunctionality. Herein, a sandwich-like structural design that rationally combines graphene nanoplatelets (GNPs), hexagonal boron nitride nanosheets (BNNSs) and cellulose nanofibers (CNFs) is presented toward multifunctional trilayer TIMs enabling high thermal conductivity, EMI shielding, electrical insulation, mechanical compatibility and flame retardancy. The top and bottom BNNSs serve as electrically insulating yet thermally conductive layers while the GNPs in the central layer mitigate EMI and the CNFs as a binder complete the mechanical properties for the lamella-like trilayers. The resulting TIM exhibits a high in-plane thermal conductivity (25.5 W/m·K), and the LED cooling system using the TIM demonstrates the capability of reducing the operating temperature. Furthermore, it shows a high-volume resistivity (4.12 × 1013 Ω cm) and EMI shielding effectiveness (29.0 dB) at X-band frequencies. Its mechanical robustness is confirmed with tensile strength and elongation of 65.0 MPa and 2.36 %, and the high flame retardancy is validated. The outcomes will inspire tailoring multifunctional TIMs using lamellar structures that optimally combine micro/nanomaterials.